1. Field of the Invention
The present invention relates to a portable telephone, an imaging system employing portable telephones and an imaging method, and more particularly, it relates to a portable telephone including an imaging portion, an imaging system employing portable telephones and an imaging method.
2. Description of the Background Art
A portable telephone including an imaging portion is known in general, as disclosed in each of Japanese Patent Laying-Open Nos. 2005-101867, 2005-323254 and 2003-219043, for example.
The aforementioned Japanese Patent Laying-Open No. 2005-101867 discloses a portable telephone (a camera-side portable telephone), having a camera function, capable of executing an imaging operation in response to an incoming signal from another portable telephone (an operating-side portable telephone) having a previously registered telephone number. This portable telephone is formed to establish a telephone call state by receiving a transmission signal (a call signal) from the operating-side portable telephone and to thereafter perform the imaging operation in the telephone call state on the basis of a prescribed operation from the operating-side portable telephone. The aforementioned “telephone call state” denotes a state where the portable telephones are connected with each other through a communication line so that the users of the portable telephones can talk to each other.
The aforementioned Japanese Patent Laying-Open No. 2005-323254 discloses a camera phone (a camera-side portable telephone) capable of executing an imaging operation in response to an incoming signal from a remote portable telephone (an operating-side portable telephone). This camera phone is formed to establish a telephone call state by receiving a transmission signal (a call signal) from the operating-side portable telephone and to thereafter perform the imaging operation in the telephone call state on the basis of a prescribed operation from the operating-side portable telephone.
The aforementioned Japanese Patent Laying-Open No. 2003-219043 discloses a folding camera phone, capable of executing an imaging operation on the basis of an operation from a remote operating terminal (a PC or another portable telephone). This folding camera phone (a camera-side portable telephone) is formed to perform the imaging operation in response to a control command such as an instruction for executing the imaging operation transmitted from the remote operating terminal accessing a common carrier server and received via the common carrier server. Further, the camera-side portable telephone is formed to transmit data of an acquired image to the operating terminal via the common carrier server. A system of transmitting/receiving a message including the control command or a message accompanied by the data of the acquired image is applied to communication between the folding camera phone and the operating terminal.
However, each of the camera phones described in the aforementioned Japanese Patent Laying-Open Nos. 2005-101867 and 2005-323254 is formed to perform the imaging operation in the telephone call state established by receiving the transmission signal (the call signal) from the operating-side portable telephone. Therefore, if some communication state (some telephone call state) has already been established between the camera-side portable telephone and a portable telephone other than the operating-side portable telephone or a wireline telephone, for example, communication (the telephone call state) between the camera-side portable telephone and the operating-side portable telephone whose user intends to instruct the camera-side portable telephone to perform the imaging operation can conceivably not be established. In other words, the telephone call state between the camera-side portable telephone and the operating-side portable telephone whose user intends to instruct the camera-side portable telephone to perform the imaging operation cannot be ensured until the communication state between the camera-side portable telephone and the portable telephone other than the operating-side portable telephone or the wireline telephone is cut off. Therefore, the user of the operating-side portable telephone cannot communicate with the camera-side portable telephone at desired timing, and hence the camera-side portable telephone cannot perform the imaging operation at timing desirable for the user.
The folding camera phone described in the aforementioned Japanese Patent Laying-Open No. 2003-219043 is formed to communicate with the operating terminal according to the communication system based on transmission/receiving of the message including the control command via the common carrier server. If the common carrier server causes a network delay or the like, therefore, immediacy of the control command from the operating terminal to the camera-side portable telephone is conceivably not implemented. In the communication system based on transmission/receiving of the message, further, a message or a telephone call from a third party different from the operating terminal may interruptively reach the camera-side portable telephone while the user of the operating terminal remote-controls the camera-side portable telephone from the operating terminal, and hence the remote control from the operating terminal is conceivably temporarily interrupted. Therefore, the user of the operating terminal cannot communicate with the camera-side portable telephone at desired timing, and hence the camera-side portable telephone cannot perform the imaging operation at timing desirable for the user.